 | T S. Taylor - 1880 - 152 pages
...FD C being an equilateral triangle). (/) .-. the angle DCF is equal to the angle ECF. and Syllogism. When a straight line, standing on another straight line, makes the adjacent angles equal, each of the angles is called a right angle (Euc. Def. 10). The straight line FC standing on the straight... | |
 | William Schofield Binns - 1881 - 214 pages
...straight lines to one another, meeting or cutting each other in a point, as (10) "When a straight lino standing on another straight line makes the adjacent...stands on the other is called a perpendicular to it." The angles AB c, A n D, are right angles. Obi. 1 . Because DB is in the same straight line with B c,... | |
 | Marianne Nops - 1882 - 278 pages
...than a right angle, called acute (Lat. acutus, sharp). These are thus defined by Euclid : — 10. ' When a straight line standing on another straight...stands on the other is called a perpendicular to it.' 11. 'An obtuse angle is that which is greater than a right angle.' 12. 'An acute angle is that which... | |
 | Euclides - 1883 - 176 pages
...= FE (Def. 17), .-. A DCF = A ECF (/. 8), and .-. L DCF = L ECF, and these are adjacent angles. But when a straight line standing on another straight...another, each of the angles is called a right angle. .-. CF is at right angles to AB, and is drawn from the given point CQEF NSte.— Since an angle may... | |
 | Euclid, Isaac Todhunter - Euclid's Elements - 1883 - 428 pages
...from the centre G ; [I. Definition 15. therefore the angle ADG is equal to the angle BDG. [I. 8. But when a straight line, standing on another straight...another, each of the angles is called a right angle ; [I. Definition 10. therefore the angle BDG is a right angle. But the angle BDF is also a right angle.... | |
 | Stephen Thomas Hawtrey - 1884 - 184 pages
...leads on to the Definitions 10, 11, and 12 of Euclid, which are as follows : Definition 10.—When a straight line standing on another straight line...stands on the other is called a perpendicular to it. Definition}.}..—An obtuse angle is that which is greater than a right angle. Definition 12.—An... | |
 | Euclides - 1884 - 434 pages
...a straight line stands on another straight line, and makes the adjacent angles equal to each other, each of the angles is called a right angle ; and the...stands on the other is called a perpendicular to it. CUD Thus, if AB stands on CD in such a manner that the adjacent angles ABC, ABD are equal to one another,... | |
 | Euclides - 1884 - 214 pages
...together equal to two right angles. Axiom 1. Therefore, the angles which &o. QE Ti. Definition 10. When a straight line standing on another straight...the adjacent angles equal to one another, each of these angles is called a right angle. Proposition XL A straight -line may be drawn at right angles... | |
 | Euclides - 1884 - 94 pages
...equal to the base ; therefore the angle is equal to the angle ; and these are adjacent angles. But when a straight line standing on another straight...the adjacent angles equal to one another, each of them is a right angle, and the straight line which stands upon the other is called a perpendicular... | |
 | American periodicals - 1884 - 862 pages
...same straight line [plane]. X. When a straight line [plane] standing on another straight line [plane] makes the adjacent angles equal to one another, each of the angles is called a right angle [right dihedral angle]. XV. A circle [cone of revolution with vertex at the eye] is a figure contained... | |
| |
When a straight line standing on another straight line makes the adjacent angles equal to one another, each of the angles is called a right angle ; and the straight line which stands on the other is called a perpendicular to it. 
